19. b--Attached Memorandum, para 5-4a, fig.
Sketch 3 in figure 5-2 shows a signal generator being used for signal
For checkpoints 1 through 5, the signal generator is set for an
As the output of the generator is applied to each
checkpoint, if the circuits are good a tone is heard in the speaker.
checkpoint 5 produces a tone, you know that the audio stages are good.
generator must be set to produce a modulated IF (455 kHz). This signal is applied
to the checkpoints starting at number 7 and working toward the mixer.
trouble is in the RF stage, you will hear a tone from all checkpoints through the
output of the mixer. Now set the generator for an unmodulated RF (1,000 kHz) and
apply the signal to the RF input of the mixer. If a tone is heard you know that
the oscillator is good. Your trouble must be located between the antenna and the
RF input of the mixer.
You have set the signal generator to three different
20. d--Attached Memorandum, para 5-3, 5-4c